When the topic of using OS X comes up, I tell people that if you drink Apple’s kool-aid and use its apps religiously—Mail, Address Book, iCal, iPhoto—then it will pay off for you. Since they hook into each other, and other apps hook into them as well, you really do get synergistic benefits. For example: if you keep all your contacts in Address Book, you can filter your mail in useful ways. If you create groups in Address Book to categorize your contacts, mail filters can be more useful.

I filter my mail based on whether the sender is in my clients group or my friends group; each goes to its own mailbox, and other actions are triggered as well.

When I receive messages from friends, their names are spoken aloud to me using this script.

When I receive messages from clients, the “work bell” rings (this is something Mail can do on its own), and a Growl notification appears on-screen using this script. I’d like to make it so that clicking on the notification blob opens the message in question, but I haven’t figured that part out yet. These notification blobs are actually pretty intrusive (they sit there until you click on them to dismiss them), but this was an intentional decision: if it’s work-related, I probably want to be interrupted.

When I receive messages from people I’ve never corresponded with before, it’s very likely those messages are spam. So I filter messages where the sender is not on my previous recipients list (this is a handy, and I suspect little-known feature in Mail) to a “holding pen” mailbox that is essentially a waiting room for my junk box. This makes it a little easier to prioritize and batch-process mail in the eternal struggle for inbox zero.

Recently, I discovered DockStar–this lets me see how many messages are in each of several boxes. This alone would almost be enough, but I like the extra channels of information I get.